A Cluster of Major Specific Resistance Genes to Leptosphaeria maculans in Brassica napus

Open Access

1 June 2004

journal article
Published by Scientific Societies in Phytopathology®

Vol. 94 (6) , 578-583
https://doi.org/10.1094/phyto.2004.94.6.578

Abstract

Two types of genetic resistance to Leptosphaeria maculans usually are distinguished in Brassica napus: qualitative, total resistance expressed at the seedling stage and quantitative, partial resistance expressed at the adult plant stage. The latter is under the control of many genetic factors that have been mapped through quantitative trait loci (QTL) studies using 'Darmor' resistance. The former usually is ascribed to race-specific resistance controlled by single resistance to L. maculans (Rlm) genes. Three B. napus-originating specific Rlm genes (Rlm1, Rlm2, and Rlm4) previously were characterized. Here, we report on the genetic identification of two novel resistance genes, Rlm3 and Rlm7, corresponding to the avirulence genes AvrLm3 and AvrLm7. The identification of a novel L. maculans- B. napus specific interaction allowed the detection of another putative new specific resistance gene, Rlm9. The resistance genes were mapped in two genomic regions on LG10 and LG16 linkage groups. A cluster of five resistance genes (Rlm1, Rlm3, Rlm4, Rlm7, and Rlm9) was strongly suggested on LG10. The relation between all these specific resistance genes and their potential role in adult-plant field resistance is discussed. These two Rlm-carrying regions do not correspond to major QTL for Darmor quantitative resistance.

Keywords

This publication has 31 references indexed in Scilit:

Chromosomal Deletion in Isolates of Phytophthora infestans Correlates with Virulence on R3, R10, and R11 Potato Lines
Molecular Plant-Microbe Interactions®, 2001
Stability of QTL for Field Resistance to Blackleg across Two Genetic Backgrounds in Oilseed Rape
Crop Science, 2001
A Field Method for Evaluating the Potential Durability of New Resistance Sources: Application to the Leptosphaeria maculans-Brassica napus Pathosystem
Phytopathology®, 2000
The Race-Specific Resistance Gene to Powdery Mildew, MlRE, Has a Residual Effect on Adult Plant Resistance of Winter Wheat Line RE714
Phytopathology®, 1999
Pathogenicity of Leptosphaeria maculans Isolates on a Brassica napus-B. juncea Recombinant Line
Phytopathology®, 1999
The Evolution of an Intron: Analysis of a Long, Deletion-Prone Intron in the Human Dystrophin Gene
Genomics, 1997
Resistance of oilseedBrassicaspp. to blackleg caused byLeptosphaeria maculans
Canadian Journal of Plant Pathology, 1992
Identification of markers linked to disease-resistance genes by bulked segregant analysis: a rapid method to detect markers in specific genomic regions by using segregating populations.
Proceedings of the National Academy of Sciences, 1991
Pathogenicity Grouping of Isolates ofLeptosphaeria maculansonBrassica napusCultivars and Their Disease Reaction Profiles on Rapid-Cycling Brassicas
Plant Disease, 1991
THE ESTIMATION OF MAP DISTANCES FROM RECOMBINATION VALUES
Annals of Eugenics, 1943